Beloved actor and comedian Robin Williams was found dead in his home in Tiburon, Calif. on Monday. He was 63.

The Coroner Divisions of the Marin Country Sheriff’s Office said in a statement that the cause of death is believed to be suicide by asphyxiation. "A comprehensive investigation must be completed before a final determination is made," the coroner's office said in a statement.

“Robin Williams passed away this morning. He has been battling severe depression of late. This is a tragic and sudden loss,” Williams' publicist Mara Buxbaum said in a statement emailed to BNO News. “The family respectfully asks for their privacy as they grieve during this very difficult time.”

Susan Schneider, Williams' wife, said in a statement that she was "utterly heartbroken."

"This morning, I lost my husband and my best friend, while the world lost one of its most beloved artists and beautiful human beings," Schneider wrote. "As he is remembered, it is our hope the focus will not be on Robin's death, but on the countless moments of joy and laughter he gave to millions."

Williams had long struggled with mental illness: PBSnoted that Williams "use[d] the manic and depressive cycles of his bipolar disorder to produce comedic genius on and off screen."

Read the full release from the Marin County Sheriff's department below: